Process of obtaining sulfurous acid from acid sludge.



residing at Campina,

UNITED. sfmi'-r13sJ oFFrcE.

GUs'rAv scHILDHAUsANn coNsrANrINcoNDREA, oF CAMPAINA, ROUMANIA.

PROCESS OF OBTAINING SUFQRQUS ACID :.EROM ACID To aU whom it may concern:

Be it. known that We, GUs'rAv SCHILDHAUS, manager, a subject of the King of Roumanie, Strada Industriei, Casale, SteIeLFRoumania, and CoNs'rAN'rIN CONDREA, chemist, a subject of the King of Roumania, residing at Campina, Strada I., C., Bratianu 68, Roumania, have invented v. certainl new and useful Improvements in Processes of Obtaining `Sulfurous Acid from Acid Sludge; and we do hereby declare the' following to be a full, clear, and exact vdescription'of the invention, such as will enable otherssskilled in the art to which it -appertains to make and use `the same.

It has been proposed more than once to turn to account lthe acid ltar produced in the puricationof raw minerall oils, that is petroleum or naphtha and' its distillationproducts, by means of sulfuric acid by distilling or gasifying said tar and thereby obtaining from it sulfurous acid, liquid hydroarbons and coke. None of the methods proposed have however found their way into practice because the sulfur contained in the tar was only in part obtained in the form bons. Coke.

of sulfurous acid. The sulfurous acid-was in fact partly reduced to sulfurctcd hydrogen and even sulfur, and the other byproducts have no great value owing to their indifferent qualit j y It has nonr been found, that the acid tar may be distilled with good results by introducing heated air intothe retort during distillation and thereb `oxidizing the sulfur and its compounds. n this manner three products are obtained from the tar: `1. A mixture of gases mainly'consisting of sulfurous acid, nitrogen and air and containing small uantities of carbonio acid and gaseous hy roca-rbons. 2. Liquid hydrocar- The tar is preferably vaporized at a comparatively low temperature of and 350 C, and the air introduced into the retort is preferably heated to the same temperature. The acid tar is run -ical device and transported to a closed chamber. The gases that issue fromthe retort are conducted through a cooler to condense the liquid hydrocarbons, and are then washed first by. means of heavy hydrocarbon oil and finally by means ofl concentrated sulfuric acid to remove the gaseoushydrocarbons and the last traces of the vapors of liquid hydrocarbons.

sel 4 by means of the heating coil 6. In the retort l the tar is vaporized, preferably at Y a comparatively low temperature of between 25() and 350 C. The air is preferably heated to the same temperature by y means of the heating coil Land is introduced into the retort 1 through pipev8. The coke and is continuously evacuated by the feedthe retortv 1 are conducted through the pi ev 12 and cooling coil 13 which lies within t e condenser 14. The larger part 'of the liquid hydocarbons is condensed in the cooler and fed through pipe 15 into the vessel 16. The gases escaping from the vessel 16 are'fed through pipe 17 into the scrubber A18 in which they are washed by means of heavy hydrocarbon oil which from Athe vessel 19, `through t-he pipe 20, through the scrubber 18 and the pipe 21 into the vessel 22 and back to the vessel 19 throufrh the pipe 23. The washed gases escape from the scrubber 18 through the the pipe 27 into the scrubber 25, pipe 28 Vinto the vessel 26. By washing the gases and afterward with sulfuric acid inthe tof sulfurous acid whicli'escapes throu h the .-"pipe 33,. and they are then collecte and '-may be utilized for known pur oses, parp su fume acid.

ticularly for the production o The ligure is a diagrammatic side-view of Sel 4 and pipe .5. It is heated Within the vesremaining inthe retort is porous and brittle,

ing screw 9 through the pipel l0 into theV closed chamber 11. 'The gases issuing from' is run continuously yto vessel 29 and pipe- 30 to the montejus 31' wherefrom it is fed back through the pipe 32 l Specification of Letterslatent.. Patented Apr. 26, ,11910. Application led April 16, 1909. Serial No. 490,318.

9o pipeV 24 and enter the scrubber 25, wherel theyare washed with sulfuric acid which is contained in the vessel 26 and flows through,

with heavy hydrocarbon' inthe scrubber 18'` 10ol sdrubber 25 they are freed from the last. ..1 traces of the gaseous hydrocarbons.y purified gases-consist lin their essential part f The process described may be also applied i to the tar produced in the rennof of mineral oils by means of fuining sulluric acid or sulfuric anhydrid.

lVe claim:

l. Process of producing sulfurous acid, liquid hydrocarbon, and coke from acid tar or sludge which consists in distilling said acid tar and introducing a stream of air into the retort during distillation, condensing the liquid hydrocarbons contained in thc distillation products, Washing the remaining sulfurous acid gas, and continuously removing the coke from the retort.

2. The process of producing' sulfurous acid, liquid hydrocarbons and coke from acid tar or sludge which consists in distilling said acid tar, introducing a stream of air heated to from 200-300 C. into the retort during distillation, condensing the liquid hydro-carbons contained in the distillation-products, Washing the remaining sulfurous acid gas, and continuously removing the coke from the retort.

3. The herein described process consisting in introducing acid tar or sludge into a retort and heatlng the acid tar to a temperature of between 200 and 300 C., introducing air to substantially the same temperature into said retort, whereby gases are given off, condensing part of said gases to a liquid, Washing the remaining gases with heavy hydrocarbon oil, and nally Washing said remaining gases with sulfuric acid.

In testnnony, that We claim the foregoing as our invention, We have signed our names 1n presence of two subscrlbing witnesses.

Witnesses GERHARD BERGER,

T. W. KRAFT. 

